those words marked a turning point in the civil war staking a moral dimension to the union cause. and the document became a symbol of hope for the nearly 4 million slaves held in confederate states. reg nalted washington is a senior archivist with the national archive. >> it confirmed their belief that the war should always have been a war for-- not to preserve the union but a war to free the slaves. >> reporter: written on paper rather than more durable parchment the proclamation has faded over the years from light exposure. and now spends most of the time in protective dark storage in the national archives. but it commands large crowds on those rare occasions like today when it's on public display, and even 150 years later, it retains the power to inspire. >> it's a historical document. it's something that i think is important to our country our nation and specifically african-americans. >> this is the document really that started to free the black slaves do i had to come see it. >> had to come down after researching my great grandparents all of whom were slaves. so i had to com